Cream together the unsalted butter and granulated sugar until light and fluffy, about 3-4 minutes.
In a separate bowl, whisk together the all-purpose flour, baking powder, and salt. Gradually add to the butter and sugar mixture, mixing until just combined.
Add milk and vanilla extract, mixing until the dough comes together. If too crumbly, add more milk, one teaspoon at a time.
Preheat oven to 350°F (175°C). Line baking sheets with parchment paper. Scoop dough using a tablespoon, roll into balls, flatten slightly, and make a hole in the center.
Bake for about 10-12 minutes, or until edges are lightly golden. Cool on the baking sheet for 5 minutes before transferring to a wire rack.
Toast shredded coconut on a baking sheet at 350°F (175°C) for 5-7 minutes, stirring halfway through.
In a small saucepan over low heat, combine caramel sauce and 4 tablespoons of milk. Stir until smooth and heated through.
Spread a layer of caramel on each cookie, sprinkle with toasted coconut, gently pressing down to adhere.
Melt chocolate using a double boiler or microwave until smooth, stirring regularly.
Dip the bottom of each cookie in melted chocolate, then drizzle more chocolate over the tops.
Allow chocolate to set completely before serving, or refrigerate for about 30 minutes to speed up the process.
